Plekhanov was not only the father of social democracy in Russia but also a Marxist theoretician of international renown. Yet when the Bolsheviks came to power in October, 1917, Plekhanov found himself not among the victors. This brief essay explains this personal tragedy as a consequence of Plekhanov``s acceptance of Marxism as a closed system of dialectical materialism. Plekhanov joined the revolutionary movement initially as a populist of the Bakuninist bent emphasizing the absolute requirement of mass participation in the coming socialist revolution as opposed to the Tkachevian notion of conspiratorial seizure of power. He was converted to Marxism because he saw it as a philosophical system which guaranteed the eventual victory of socialism and recognized the positive role capitalism and the bourgeoisie were to play. Although Plekhanov tried to make due allowance for the role of individual personalities in history and cautioned against excessive reliance on spontaneity of the masses, he was even more wary of any attempt to force the pace of history. Plekhanov recognized that the development of capitalism in Russia followed a pattern somewhat different from what Marx had in mind, but, unlike Lenin, adamantly refused any necessity to adjust the theory to a reality vastly different from that upon which it had originally been founded. In the end, it was his dogmatic insistence upon the narrowly defined orthodoxy and the idealistic hope to fit the Russian reality into the Procrustean bed of revolutionary Marxism that proved to be Ptekhanov``s undoing.